Blocking circuit for inboard engine ignition

ABSTRACT

A blocking circuit is provided in combination with an inboard motorboat engine, blower, and ignition circuit which prevents actuation of the ignition circuit until after the blower has operated for a predetermined period of time to ventilate the engine compartment. A time-delay switch is operated by a bloweractivated switch in circuit with the ignition circuit. Upon actuation of the blower, the blower-activated switch closes energizing the time-delay switch. After a predetermined time interval, the time-delay switch closes and completes the ignition circuit whereupon the craft may be started and operated in a conventional manner. An emergency ignition switch is also provided in parallel with the blocking circuit to allow operation of the engine in the event of an emergency. Use of the emergency switch renders it inoperative requiring that it be replaced after such use to prevent indiscriminate subsequent use by an unconscionable operator.

United States Patent Abplanalp et al.

[ 1 July 4, 1972 [541 BLOCKING CIRCUIT FOR INBOARD ENGINE IGNITION [72] Inventors: George W. Abplanalp, Belmont; Steve Corson, Luther, both of Mich.

[22] Filed: July 6,1971

[21] Appl.No.: 159,666

[52] US. Cl. .307/9,114/211,115/.5 R [51] ..II02j l/00 [58] Field olSeareh ..307/9,10,116,141,141.4, 307/141.8; 114/211; 115/.5 R; 123/179 A; 98/1; 303/19 [56] References Cited UNITED STATES PATENTS 3.599591 8/1971 Edelson ..307/9 3.489.912 l/1970 Hoffman, Jr .l ..307/9 Primary Examinerl'lerman J. Hohauser AttorneyPrice, l-leneveld, Huizenga & Cooper [57] ABSTRACT A blocking circuit is provided in combination with an inboard motorboat engine, blower, and ignition circuit which prevents actuation of the ignition circuit until after the blower has operated for a predetermined period of time to ventilate the engine compartment A time-delay switch is operated by a blower-activated switch in circuit with the ignition circuit. Upon actuation of the blower, the blower-activated switch closes energizing the time-delay switch. After a predetermined time interval, the time-delay switch closes and completes the ignition circuit whereupon the craft may be started and operated in a conventional manner. An emergency ignition switch is also provided in parallel with the blocking circuit to allow operation of the engine in the event of an emergency. Use of the emergency switch renders it inoperative requiring that it be replaced after such use to prevent indiscriminate subsequent use by an unconscionable operator.

6 Claims, 9 Drawing Figures E To Ignition PATENTEDJUL 41972 SHEET 10F 2 FIG. I

l J T 30' To Ignition 38 FIG. 3

READY PRE.IGN

EMER. IGN.

INVENTORS GEORGE W. ABPLANALP FIG. 2

STEVE CORSON I PATENTEDJUL 4 I972 sum 2 or 2 mvsmoas GEORGE w. AB-PLANALP STEVE CORSON BLOCKING CIRCUIT FOR INBOARDENGINE IGNITION BACKGROUND OF THE INVENTION The confinement of an engine to a c'losed compartment ina motorboat requires that the accumulated fumesinthe engine compartment be completely exhausted therefrom prior to the connection of the power supply to the ignition circuit and the subsequent starting of the engine. Failure to adequately ventilate the engine compartment can result in the accumulation of explosive gases resulting in an explosion capable of destroying the boat and everythingon it.

The conventional approach tothis problem has been to rely on the operator to remember to vent the compartment prior to ignition. It will be readily apparent that such an approach is dangerous due not only to the fallibility and forgetfulness of human operators but in addition due to the reluctance on the part of the operator to wait the additional few minutes for the blower to remove the accumulatedfumes in the compartment. Various ignition control systems have been proposed to prevent the starting of the engine until after it has been determined that fumes no longer exist in the engine compartment. The Hoffmam'Jr. U. S. Pat. No. 3,489,912 and the VanRanst U. S. Pat. No. 3,315,584 are examples of such starting systems. Each of these devices disclosed starting systems for motor boats. These systems include a delay mechanism for preventing engine ignition for a predetermined time and a blower motor to vent the engine compartment. In addition, each of these systems relies principally upon a combustible vapor detector located within the engine compartment to detect the presence (or absence) of combustible vapor. If the sensor indicates the absence of fumes, the ignition circuit is rendered operative and the engine may be started. Unfortunately, however, present state-of-the-art vapor detectors of this type having any degree of accuracy and reliability are extremely expensive. Some are, however, lower in cost but their reliability and accuracy leave much to be desired. In addition, devices which rely upon a vapor detector are not always practical because the detector will measure the concentration of fuel vapors only in the immediate vicinity of the detector head. Therefore, an explosion could result if combustible vapors were present in some other area of the enginecompartment.

Zurit, et a1. U. S. Pat. No. 2,526,446 discloses an ignition system for boats having a mechanical timer switching mechanism to operate a blower in theengine compartment of the craft prior to the actual closing of the ignition circuit.

Each of the above-mentioned starting systems block operation of the ignition circuit until the blower has been operated to change the air in the engine compartment. The systems are relatively complicated and in the event of a component failure, the entire system is rendered inoperative. In addition, there are occasions when'danger is imminent and the starting system must immediately be rendered operative.

Hoffman, Jr. provides an override or emergency ignition switch which serves to completely bypass the vapor detector and time-delay circuitry and allows for the application of power from the battery directly to the ignition circuit. Starting systems which do not have an emergency-start provision to bypass the ignition or blocking circuit systems are, of course, unsafe as the operator must be able to start the engine and move the boat out of a dangerous situation immediately. Starting systems which are designed with an override or emergency ignition system are virtually. useless particularly when an unconscionable operator who, in his haste to get underway as quickly as possible, completely ignores the normal time-delay starting circuit.

Some of the more sophisticated systems are designed to stop the engine if fuel vapors build up while the boat is underway. These systems, of course, are quite unsafe because if engine power is lost without warning, the boat and the operator are placed at the mercy of the wind, the tide, or the current and could result in a collision or running aground before the operator has time to lower his anchor.

SUMMARY OF THE INVENTION This inventionrelates to a safety device for use in inboard motorboats which precludes the actuation of the ignition prior to the immediately preceding venting or expelling of fumes from the engine compartment. In addition, the invention provides an override or emergency ignition switch which because of its'construction canbe operated only one time. When the emergency switch has been turned ofi, the switch cannot be returned to its on position and replacement is required. This factor alone which provides for safety operation also serves as a deterrent to the unconscionable operator and in the absence of an actual emergency he will be compelled to rely on the time-delayed ignition system which vents the engine compartment prior to actual ignition. Specifically, there is provided an improved combination of an inboard boat engine, an ignition circuit for the engine, a blower adapted for blowing fumes out of the engine compartment, a switch responsive to operation of the blower, and a blocking means for automatically blocking or delaying the ignition circuit from actuation until after the blower has functioned a predetermined length of time. An emergency switch is also provided which operates to bypass the blocking circuit for emergency use which switch can be used only one time, thereafter requiring complete replacement.

Accordingly, it is an object of this invention to provide a circuit which will prevent explosions on inboard motorboats due to the failure of the operator to properly ventilate the engine compartment prior to starting the engine.

It is another object of this invention to provide an ignition circuit which will automatically prevent actuation of the circuit until after the fumes have been expelled from the engine compartment.

It is yet another object of thisinvention to provide an ignition circuit which will preclude ignition if the blower for the engine compartment is not operating properly.

It is a related object of the invention to provide an override or emergency switch which will render the ignition system operative immediatelybut which once used must be replaced, thereby preventing indiscriminate use thereof.

Other objects and advantages of the invention will become apparent upon reference to the following drawings in detailed discussion.

BRIEF DISCUSSION OF THE DRAWINGS FIG. 1 is a partially schematic elevational view with parts in section of an inboard motorboat utilizing the invention;

FIG. 2 is a partial elevational view illustrating a portion of a control panel for the motorboat;

FIG. 3 is a schematic circuit diagram illustrating a blocking circuit constructed in accordance with the invention;

FIGS. 4, 5 and 6 are front elevational views of the emergency switch of the invention shown in its various operating positions; and

FIGS. 7, 8 and 9 are cross-sectional views taken along the planes VIl-VII, VllI-VIII and IX-IX of FIGS. 4, 5 and 6, respectively, illustrating the operation of the switch in its various operating positions.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to the drawings, FIG. 1 illustrates the invention as providing a safety circuit for the operation of an engine 10 in an inboard motorboat 12. The engine is normally located in a closed engine compartment 14. A blower 16 is conventionally utilized to vent the compartment 14 by expelling the fumes from the compartment through a conduit to an exit port 18. Switch 24 is provided in the conduit at the outlet side of the blower 16 to detect the flow of air to the exit port 18.

The craft may be controlled in a conventional manner from the enclosed cabin 20 or from an upper bridge 22 each of these areas having duplicate steering, ignition, and like control mechanisms arranged in a conventional manner. As illustrated in FIG. 2, each of these control panels, in addition to the usual conventional controls, also include a key-operated, preignition switch 26, a ready indicator light 28, and a keyoperated, emergency ignition switch 30. It being understood, of course, that one or any number of individual control panels may be provided depending upon the design of the craft.

Referring now to FIG. 3, the blocking circuit of the invention is illustrated in schematic form. In accordance with the invention, the blocking circuit is provided to prevent by means of switch 36 the connection of the ignition circuit 38 (not shown) to the craft power supply 34 until after the blower 16 has operated a predetermined time to vent fumes from the engine compartment 14. A switch 24, operable in response to movement of air from the blower 16 through the conduit, applies current to the time-delay switch 36 thereby preventing its operation until after the blower has started to operate. As will be more fully explained hereinafter, an emergency ignition switch 30 is also provided in parallel with the blocking circuit to connect the battery power supply 34 directly to the ignition circuit 38 when an emergency situation arises.

The preignition switch 26 is connected by line 40 to one side of the battery power supply 34 and is provided with an off" position (D) and an on" position (E). When it is desired to start the engine under normal operating conditions, switch 26 is moved from position D" to position E completing an electrical circuit between power supply 34 to the blower motor 16 through line 42. As illustrated, the opposite side of the blower motor 16 is grounded in a conventional manner. One side of normally opened air sensing switch 24 is also connected to line 42. As described in connection with FIGal, switch 24 is located in the air outlet conduit. Operation of the blower will, therefore, cause the contacts of switch 24 to close allowing the current to flow through the contacts and through line 44 to the heater elements 46 of thermal time-delay relay 36 to ground.

v As the blower commences operating, switch 24 closes and the current is applied to the heater elements 46 of the timedelay 36 causing the contacts 48 to close after a predetermined time. Preferably, the time delay is on the order of approximately l minutes; however, this may be varied to suit the size of the engine compartment, the capacity of the blower, or like parameters.

As contacts 48 close, one of them being connected by line 42 and switch 26 to the battery 34, the current is applied to the ignition circuit 38 through line 50 and to the indicator lamp 28 through line 51 to ground indicating that the engine compartment 14 has been vented and that the engine may be safely started.

In the event an emergency situation should arise and the engine must be immediately started, an emergency ignition or override switch 30 is provided to directly connect the power supply 34 to the ignition circuit 38. The emergency switch is provided with a movable contact arm 52 connected by line 54 to the battery power supply. The opposite side of the switch is provided with three contact positions labeled A, B and C. Position A is a normally off position. Position B is an emergency ignition on position and connects the power supply directly to the ignition circuit 38 to line 56. As will be more fully described in connection with FIGS. 3 through 8, when the switch has been moved to position B, i.e., the ignition on position, the engine can only be stopped by moving the switch to the C position. It cannot be returned to the A position. Once the switch has been moved to the C position, it cannot be returned to the on" or B position. The switch must be replaced with a switch in the A or off position. This feature insures that the engine will not be operated except in the case of an emergency thereby preventing an operator in his haste to get underway" from bypassing the normal time-delayed starting procedures.

Since the craft may often be operated from the bridge 22 rather than the closed cabin 20, it is desirable to provide a duplicate set of controls on the bridge control panel. These duplicate controls are illustrated in phantom in block 58 in FIG. 3 and include a preignition switch 26', an indicator lamp 28', and an emergency ignition switch 30' connected in parallel to the circuit previously described. The operation is the same as that previously described. It is also understood that separate similar circuits may be provided for craft having multiple engines and multiple engine compartments or that several blowers and ignition circuits may be controlled by the circuit described above.

Referring now to FIGS. 4 through 9, the emergency ignition switch 30 for use with the above-described circuit will be described in detail. Basically, switch 30 comprises two relatively movable sections. The movable contact 52 is carried on a rotatable section 60 and a relatively fixed supporting structure 62 is provided to carry the fixed contact member B (FIG. 7). The fixed supporting structure 62 additionally carries a plurality of biased pin members to control the rotation of the relatively movable parts as will be more fully set out hereinbelow. The two sections 60 and 62 are rotatable with respect to each other and may be rotatably secured at their center section by means of a centrally located conventional lock and.

tumbler arrangement 64. constructional details of such lock are well known to those skilled in the art and they will not be described herein in detail. Preferably, the same key utilized to operate the preignition switch 26 will also be utilized to operate the emergency switch 30.

The movable contact element 52 is in the form of a terminal 65 threadable received in and passing through the rotatable section 60. The opposite end of the terminal is threaded and provided with conventional fastening means thereon for securement to the line 40 connected in circuit with the power supply 34 of the craft (FIG. 3). A similar terminal 66 having connecting means thereon extends from the opposite side of the switch in the support section 62 and may be connected to line 56 to the ignition circuit 38.

The terminal 66 extends into the supporting structure 62 a short distance where a slightly enlarged opening 68 is provided. Mounted within the opening 68 is a contact ball 70 and bias spring 72 which serves to bias the contact ball 70 toward the movable section 60. The terminal 66, the bias spring 72, and the contact ball 70 are each formed of conductive material and are electrically connected to each other to form contact section B. The rotatable section of the switch 60 is provided with a series of detents or recesses at the positions labeled A, B and C. These recesses are located on an are so that as the switch is rotated about the central portion thereof, the ball 70 will be biased by the spring 72 into one of the recesses A, B or C. As illustrated in FIGS. 4 and 7, the ball 70 is biased into recess A thereby assuming an off position of the switch as shown in FIG. 3.

The supporting section 62 also carries a pair of pin members 76 and 78. These pins are movable laterally within section 62 in openings 80 and 82 provided therein. The openings 80 and 82 are enlarged at the center portion of section 62 to receive bias springs 84 and 86 which serve to bias the pins 76 and 78 toward the movable section 60.

Upon the occasion of an emergency, the key is inserted in the lock 64 and the rotatable switch section 60 is turned to the on or B position. As illustrated in FIGS. 5 and 8, the switch rotates in a clockwise direction as indicated by the arrows 88. As the terminal B detent comes into alignment with the ball 70 electrically connected to terminal 66, electrical contact is made through the switch applying the current from battery 34, line 40, contact 52, terminal B, ball 70, bias spring 72, terminal 66, and through line 56 to the ignition circuit 38 (FIG. 3). The movable section 60 of the switch is provided with an elongated slot 90 and an opening 92. The slot and opening each have a width or diameter slightly larger than the diameter of the pin members 76 and 78. The slot 90 is arc-shaped having a length along the radius equal to the distance between detents B and C. Simultaneously, with the positioning of the ball 70 in the detent B closing the circuit, pin 78 is biased by the spring 86 into the elongated slot 90 thereby preventing the switch from being turned in a counterclockwise direction toward the A position. The boat may be then started and operated in a conventional manner.

After the boat has been moved out of the danger area, the engine may be turned ofi by continuing the rotation of the rotatable switch of section 60 in a clockwise direction. This clockwise movement continues until the ball 70 is positioned in the detent C. The slot 90 moves with the switch until the pin 78 contacts the opposite end of the slot. At the same time, opening 92 comes into alignment with the pin 76 and pin 76 is biased by spring 84 into the opening 92. The switch is then looked in the C or off position and cannot be rotated in either direction. The switch 30 must be disassembled and reset to the A ofi' position or completely replaced with a new switch. The preignition switch 26, of course, may be utilized in a conventional manner regardless of the position of the emergency ignition switch 30.

For convenience and ease of manufacture, the switch 30 may be constructed of plastic-like materials. It is therefore relatively inexpensive and its replacement cost is not objectionable. Ideally, the switch will be encapsulated utilizing any of the various well-known encapsulation techniques to protect the mechanisms from environmental conditions as well as to prevent unauthorized tampering.

In view of the above disclosure, it will be readily apparent to those skilled in the art that the present invention provides a novel blocking and starting circuit for inboard motorboats. The system is also seen to include a novel bypass or emergency ignition switch which allows instant operation of the motor should an emergency condition exist but which will prevent the careless operator from indiscriminately bypassing the starting system. It is also to be noted that the blower is continuously operating wherever the switch is turned on and whenever the engine is running. This prevents build up of fumes within the engine compartment whether the boat is operated at slow trolling speeds, at full speed, or at anchor.

While a preferred embodiment of the invention has been shown and described, it will be apparent that equivalent arrangements can be made which practice the invention. Thus, it is intended that the invention cover the equivalent arrangements unless the following claims by their wording expressly state otherwise.

The embodiments of the invention is which an exclusive property or privilege is claimed are defined as follows:

1. In a motorboat having an engine compartment, an engine, an ignition for said engine, a power supply for said ignition system, and a blower for ventilating said engine compartment, a blocking circuit connected in circuit between said power supply and said ignition system to insure operation of said blower for a predetermined time prior to operation of said engine comprising: a time-delay relay having a coil and a pair of normally opened contact elements; an air switch having a pair of normally opened contact elements positioned adjacent the outlet end of said blower, said air switch responsive to the operation of said blower to thereby close said contacts; first circuit means connecting said power supply to said blower, to one of said contacts on said air switch, and to one of said contacts on said timedelay relay; second circuit means connecting the other of said contacts on said air switch to said coil of said time-delay relay; and third circuit means connecting the other of said contacts on said time-delay relay to said ignition circuit; whereby operation of said blower closes said air switch connecting said first circuit to said second circuit thereby connecting said time-delay relay coil to said power supply, said time-delay relay contacts remaining in a normally opened position a predetermined time after such connection whereupon said contacts close connecting said first circuit means to said third circuit means thereby connecting said power supply to said ignition system.

2. An ignition blocking circuit as described in claim 1 and further comprising: fourth circuit means connected in parallel with said first, second, and third circuit means between said power supply and said ignition system; and normally opened switch means connected in series with said fourth circuit means.

3. The ignition blocking circuit as described in claim 2 wherein said normally opened switch means comprises: a fixed contact terrmnal and a movable contact terminal said movable contact terminal movable from a first normally opened position to a second closed position and thence to a third open position; and means in said switch to prevent movement of said movable contact terminal from said second position to said first position and from said third position to said second position.

4. The ignition blocking circuit as described in claim 2 wherein said switch means further comprises: a supporting section having a fixed contact terminal mounted thereon; a movable section having a movable contact terminal fixed thereon, said supporting section and said movable section being relatively rotatable with respect to each other; pin means in said supporting section; means biasing said pin means in said supporting section toward said movable section; and means in said movable section to receive said biased pin means as said movable section is rotated with respect to said support section to prevent counterrotation thereof.

5. An apparatus as described in claim 4 and further including locking means in said supporting section cooperable with said movable section to prevent relative movement therebetween when said movable section has been moved to said third position.

6. An apparatus as defined in claim 5 wherein said locking means comprises pin means in said supporting section and; biasing means for said pin means urging said pin means toward said movable section, said movable section having an opening therein adapted to receive said pin means when said movable section is moved to said third position. 

1. In a motorboat having an engine compartment, an engine, an ignition for said engine, a power supply for said ignition system, and a blower for ventilating said engine compartment, a blocking circuit connected in circuit between said power supply and said ignition system to insure operation of said blower for a predetermined time prior to operation of said engine comprising: a time-delay relay having a coil and a pair of normally opened contact elements; an air switch having a pair of normally opened contact elements positioned adjacent the outlet end of said blower, said air switch responsive to the operation of said blower to thereby close said contacts; first circuit means connecting said power supply to said blower, to one of said contacts on said air switch, and to one of said contacts on said time-delay relay; second circuit means connecting the other of said contacts on said air switch to said coil of said time-delay relay; and third circuit means connecting the other of said contacts on said time-delay relay to said ignition circuit; whereby operation of said blower closes said air switch connecting said first circuit to said second circuit thereby connecting said time-delay relay coil to said power supply, said time-delay relay contacts remaining in a normally opened position a predetermined time after such connection whereupon said contacts close connecting said first circuit means to said third circuit means thereby connecting said power supply to said ignition system.
 2. An ignition blocking circuit as described in claim 1 and further comprising: fourth circuit means connected in parallel with said first, second, and third circuit means between said power supply and said ignition system; and normally opened switch means connected in series with said fourth circuit means.
 3. The ignition blocking circuit as described in claim 2 wherein said normally opened switch means comprises: a fixed contact terminal and a movable contact terminal said movable contact terminal movable from a first normally opened position to a second closed position and thence to a third open position; and means in said switch to prevent movement of said movable contact terminal from said second position to said first position and from said third position to said second position.
 4. The ignition blocking circuit as described in claim 2 wherein said switch means further comprises: a supporting section having a fixed contact terminal mounted thereon; a movable section having a movable contact terminal fixed thereon, said supporting section and said movable section being relatively rotatable with respect to each other; pin means in said supporting section; means biasing said pin means in said supporting section toward said movable section; and means in said movable section to receive said biased pin means as said movable section is rotated with respect to said support section to prevent counterrotation thereof.
 5. An apparatus as described in claim 4 and further including locking means in said supporting section cooperable with said movable section to prevent relative movement therebetween when said movable section has been moved to said third position.
 6. An apparatus as defined in claim 5 wherein said lockinG means comprises pin means in said supporting section and; biasing means for said pin means urging said pin means toward said movable section, said movable section having an opening therein adapted to receive said pin means when said movable section is moved to said third position. 